fix color system render (#2360)

* fix color system render

* changelog

CHANGELOG.md

@@ -23,6 +23,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Fixed dark mode toggles in a "child" screen not updating a "parent" screen https://github.com/Textualize/textual/issues/1999
 - Fixed "panel" border not exposed via CSS
+- Fixed broken color on macOS Terminal https://github.com/Textualize/textual/issues
 
 ## [0.20.1] - 2023-04-18
 

src/textual/strip.py

@@ -421,7 +421,7 @@ class Strip:
             Rendered sequences.
         """
         if self._render_cache is None:
-            color_system = cast(ColorSystem, console.color_system)
+            color_system = console._color_system
             render = Style.render
             self._render_cache = "".join(
                 [